Based on interviews with lawyers and others familiar with the case, both sides appear to be digging in, and a pre-trial settlement seems unlikely. The next major step is expected to be a full-blown jury trial in federal district court in Lufkin, Texas. Blackboard filed its suit about 18 months ago.

The case has become something of a cause célèbre among ed-tech specialists in colleges and schools because of a strong tradition of using open-source software for eLearning activities.

A legal victory by Blackboard, which dominates the commercial course-management market, would be counter to the goals of leading open-source advocates. To many educators, the ability to generate their own products without commercial interference is considered a fundamental right, and something to be vigorously protected.

Critics of Blackboard also see D2L's fight against a much larger competitor as a battle between David and Goliath. At D2L, a lawyer for the privately owned Canadian company has stressed repeatedly that, in resisting Blackboard, it is "fighting for the entire community," as she recently put it. Meanwhile, according to some observers, Blackboard may not have anticipated how strongly its suit against D2L would be contested.

In any case, Matthew H. Small, Blackboard's chief counsel, said in an interview last week that it was "very clear" that D2L was guilty of patent infringement. He said he was "not even thinking about" a settlement.

Desire2Learn's lawyer, Diane Lank, also held out little prospect of avoiding a trial.

She said she had been involved in many cases where her client, despite being confident, agreed to settle out of court to avoid additional costs. But she stressed that in the Blackboard case, "we have taken the position ... that there's more at stake."

Some aspects of the dispute have led to emotional charges on the internet. In a blog that D2L posted on its website toward the end of October--but that it quickly removed after hearing from opposing lawyers--the company accused Blackboard of having been disingenuous in asserting that it only wanted a "reasonable royalty" from D2L.

On the contrary, D2L's blog declared, "we've learned that months before announcing the patent and filing suit, Blackboard and its external advisors and PR firms discussed the 'public' purpose of the patent as [being] to protect intellectual property," when "the 'real' purpose was to 'contain and control' Desire2Learn."

The blog claimed that "Blackboard's litigation strategy appears to be to increase costs of litigation to Desire2Learn through unnecessary discovery and depositions, while deflecting attention from the real, fundamental issues of patent validity, infringement, and equitable conduct."